Carbon nanotubes (CNTs) are typically formed as a mixture of metallic, semimetallic, and semiconducting species of varying lengths and diameters. For many applications, particularly those in the electronics industry, separation of semiconducting carbon nanotubes from the co-produced metallic and semimetallic species would be highly desirable. Limited purity and agglomeration of as-produced carbon nanotubes can also be problematic in this respect.
Non-limiting examples of approaches that have been used to achieve some degree of separation of carbon nanotube species from one another include, for example, selective aqueous two-phase solvent partitioning, reaction with sub-stoichiometric quantities of a functionalizing species, electrochemical separation, gradient centrifugation, and the like. However, these separation processes can be difficult to perform, are costly and time-consuming, and are not readily scalable to industrially relevant quantities. Moreover, surfactants are used in many of the foregoing separation processes and can be difficult to remove from the separated carbon nanotube species. If not removed, the surfactants can interfere with various downstream processes, such as the spin-coating methods that are utilized in the electronics industry.
In view of the foregoing, improved methods for achieving high-throughput separation and/or purification of carbon nanotubes and other carbon nanomaterials would be of significant interest in the art. In particular, the ready separation and purification of semiconducting carbon nanotubes would be highly desirable. The present disclosure satisfies the foregoing needs and provides related advantages as well.